Sleeping with bed bugs affects people differently. Most experience small, itchy bites or no reaction at all, while a minority develop widespread, intense rashes. These dramatic reactions are not caused by the bites themselves—bed bug mouthparts are tiny—but by an exaggerated immune response to proteins in their saliva.
Bed bugs feed by piercing the skin, injecting saliva that prevents clotting and numbs the area. The body reacts later, sometimes mildly, sometimes severely. Repeated exposure can sensitize the immune system, causing stronger reactions over time. Severe rashes involve redness, swelling, heat, and inflammation extending beyond bite sites. People with allergies, sensitive skin, or autoimmune conditions are more likely to experience such responses.
Importantly, these rashes are not infections, disease, or evidence of bed bugs living under the skin. Most cases are mild and self-limiting. Medical attention is needed only if symptoms worsen, include pain, fever, or signs of infection.
